Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Java Java Data Structures Efficiency! Changing Course

I added the video, there are no errors. Still, the Check work button tells me that I should add the video.

What am I missing?

package com.example.model;

import java.util.List;

public class Course {
  private String mName;
  private List<Video> mVideos; 

  public Course(String name, List<Video> videos) {
    mName = name;
    mVideos = videos;

  public String getName() {
    return mName;

  public List<Video> getVideos() {
    return mVideos;

package com.example.model;

public class Video {
  private String mTitle;

  public Video(String title) {
    mTitle = title;

  public String getTitle() {
    return mTitle;

  public void setTitle(String title) {
    mTitle = title;

import com.example.model.Course;
import com.example.model.Video;

import java.util.Map;
import java.util.LinkedList;

public class QuickFix {

  public void addForgottenVideo(Course course) {
    // TODO(1):  Create a new video called "The Beginning Bits"
    Video video = new Video("The Beginning Bits");
    // TODO(2):  Add the newly created video to the course videos as the second video.
    LinkedList<Video> videos = new LinkedList<>();
    videos.add(1, video);

  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {


  public Map<String, Video> videosByTitle(Course course) {
    return null;


1 Answer

Seth Kroger
Seth Kroger
56,412 Points

It's looking for the video to be added to the course's list, not a list that's only local to the method.

Sorry, I thought videos was the course's list. I don't understand, please explain a little more.

Thank you,